How does the supercomputer predict the outcomes of the Champions League round of 16 second-leg matches?

The Opta supercomputer has issued predictions for the second-leg matches in this season's Champions League round of 16.

Chelsea vs PSG (aggregate score: 2-5)

When Khvicha Kvaratskhelia was introduced for PSG in the 62nd minute at Parc des Princes last Wednesday, with the score at 2-2, many Chelsea fans feared the talented Georgian player would make an impact, and indeed that was the case.

Kvaratskhelia contributed one assist and two goals, making the final score far more lopsided than the actual flow of the match, and helping the reigning European champions gain control over the Premier League side.

PSG could eliminate their fourth consecutive English opponent in the Champions League knockout stages, having previously overcome Liverpool, Aston Villa, and Arsenal on their path to the 2024/25 final.

It is unsurprising that the supercomputer rates PSG's chances of progression very highly. They advance in 94.1% of simulations, and even win at Stamford Bridge in 33.2% of cases. Chelsea wins 45% of simulated matches, so they are considered the favorites for the second leg, but it is difficult for them to win by a sufficiently large margin to salvage their European campaign.

Man City vs Real Madrid (aggregate score: 0-3)

This is another matchup where Man City must overturn a deficit after trailing by three goals. That is already very difficult against any opponent, especially Real Madrid, a team that has never been eliminated in 35 instances when leading by three or more goals after the first leg in European competitions.

Furthermore, Pep Guardiola has never overturned a deficit in the Champions League knockout stages after losing the first leg since his time managing Bayern Munich (quarter-finals in 2014-15 against FC Porto – won 7-4 overall). Since then, he has failed in all five attempts, including three with Man City.

Federico Valverde's hat-trick at the Bernabeu gave Real Madrid a massive advantage, and they successfully conclude the tie in 86.6% of simulations.

Guardiola's team is still rated highly by the supercomputer for winning the second leg in Manchester on Tuesday (58.5%), while Real Madrid wins in an additional 22.1% of simulations.

Of course, Real Madrid does not need to win the second leg, but if they do, Alvaro Arbeloa will become the first Real Madrid manager to win all of his first four Champions League knockout matches.

Barcelona vs Newcastle (aggregate score: 1-1)

In the first leg, Harvey Barnes seemed to have secured victory for Newcastle with a goal in the 86th minute. However, Lamine Yamal's penalty in stoppage time leveled the score, keeping the tie balanced before the second leg at Camp Nou.

That could be a more crucial equalizer than many realize. When drawing the first leg away, Barcelona has progressed in all of their last 10 Champions League knockout ties. The last time they were eliminated under such circumstances was in the 2002/03 season against Juventus in the quarter-finals.

Newcastle's domestic form has been inconsistent, but they perform well in Europe. Manager Eddie Howe's team is unbeaten in their last six Champions League matches (winning 3, drawing 3). If they win this match, it will be their first time winning two consecutive away matches in the competition, following a 6-1 victory against Qarabag in the play-offs.

Nevertheless, Barcelona is still rated higher, with a 67.1% chance of progression according to simulations. Manager Hansi Flick's team wins in 56.8% of simulations, while Newcastle wins only 21.9%. The probability of a draw (leading to extra time or penalties) is 21.3%.

Tottenham vs Atletico Madrid (aggregate score: 2-5)

Given recent events at Tottenham, it is difficult to fully grasp the significance of a Champions League round of 16 match under the lights in North London. The threat of relegation in the domestic league remains real for Tottenham, despite a hard-fought draw against Liverpool on Sunday.

Atletico displayed sharpness in the Spanish capital last week, leading 4-0 after just 22 minutes. The match ended 5-2 as Tottenham managed some recovery. However, Tottenham's hopes of overturning the deficit at home are very slim.

Tottenham's home form in the Premier League is poor, with only 2 wins in 15 matches (drawing 4, losing 9). However, in the Champions League, they perform very well at home.

They have won all four home matches in this season's Champions League with an aggregate score of 10-0, and could become the first non-Spanish team to win their first five home matches without conceding in a single season, after Deportivo La Coruña (2003/04) and Real Madrid (2010/11, 2015/16).

Still, the Opta supercomputer rates Atletico as the overwhelming favorite to progress (95.9%), though Tottenham has a slight advantage in winning the second leg (38.5%), which could help restore some confidence. Atletico also has a 37% chance of winning again in the simulations.

Arsenal vs Bayer Leverkusen (aggregate score: 1-1)

Kai Havertz shattered the hearts of his former supporters last week by successfully converting a late penalty, securing a draw for Arsenal at the BayArena.

Bayer Leverkusen matched the Premier League leaders. Robert Andrich made the Gunners pay in their own style by scoring from a corner situation, before Havertz came off the bench and equalized against his former club.

Avoiding defeat is a positive signal for Arsenal. When winning or drawing away in the first leg, they have progressed in 17 out of 20 two-legged knockout ties in European competitions.

With the home advantage in the second leg, Mikel Arteta's squad is highly rated for progression, with 79% of supercomputer simulations. Arsenal wins the second leg at Emirates in 69.8% of simulations, while Leverkusen surprises with a win in 12.8%. The remaining 17.9% end in a draw, leading to extra time and potentially penalties.

Liverpool vs Galatasaray (aggregate score: 0-1)

Mario Lemina's early goal decided the intense first leg at RAMS Park, but Liverpool will hope to utilize Anfield's power to overturn the situation on Wednesday. However, they need to perform much better than their dull draw against Tottenham last Sunday.

The Turkish side has reasons for confidence, but must improve their away record in the Champions League to complete the task. Galatasaray has lost 20 of their last 25 away matches in the competition (winning 2, drawing 3), and lost 4 of their 5 away knockout matches (only winning one, against Schalke 04 in 2013).

Despite poor form and trailing, manager Arne Slot's team is still rated higher by the Opta supercomputer with a 58.8% chance of progression. Liverpool wins in 69.9% of pre-match simulations, compared to 12.8% for Galatasaray, though the away side would also progress if it draws (17.3%).

Bayern Munich vs Atalanta (aggregate score: 6-1)

In the play-offs, Atalanta once overturned a 0-2 first-leg deficit against Borussia Dortmund to progress. However, this time they have placed themselves in a much more difficult situation against another Bundesliga opponent.

Bayern defeated Atalanta heavily in Bergamo last week with a 6-1 score. Needless to say, no team has ever overturned a five-goal deficit after the first leg in the history of the European Cup/Champions League, and the supercomputer clearly reflects that.

Frankly, the 0.1% progression chance given to Atalanta is somewhat generous. However, there is a notable variable. Bayern may be without their first-choice goalkeeper, as Manuel Neuer and Jonas Urbig are injured, and Sven Ulreich also suffered a muscle issue in the match against Bayer Leverkusen last weekend. Therefore, 16-year-old goalkeeper Leonard Prescott could debut for the first team, after being on the bench last Saturday.

Bayern is rated with a 67.4% chance of winning again at the Allianz Arena. Meanwhile, Atalanta has a 14.7% chance of securing a victory, likely only for pride.

Sporting CP vs Bodo/Glimt (aggregate score: 0-3)

The favored Norwegian side among neutral fans continues to impress. Bodo/Glimt faced the risk of elimination from the top 24 in the league-phase stage with only two matches left, but then defeated Man City and Atletico Madrid to secure a play-off spot. They proceeded to overcome Inter Milan in both legs to reach the round of 16, and now hold a significant advantage over Sporting CP, nearing a quarter-final ticket.

The 3-0 home victory last week gives manager Kjetil Knutsen's squad a strong chance to progress. If successful, this would only be the third time a Norwegian team eliminates a Portuguese representative in European cup knockout stages, after Molde (against União de Leiria, UEFA Cup 2003/04) and Viking FK (against Sporting, UEFA Cup 1999/2000).

Nevertheless, Sporting still has hope. They once overturned a three-goal deficit in a European cup knockout tie, defeating Manchester United 5-0 in the second leg of the 1963/64 European Cup Winners' Cup quarter-finals, after losing 1-4 in the first leg.

However, Bodo/Glimt is still rated much higher, with an 86.9% chance of progression according to Opta's supercomputer simulations. Sporting has a 57.2% chance of at least winning the second leg at Estádio José Alvalade, while the away side wins in 23.1% of simulations.